Lighting apparatus with luminophore on a moveable carrier

Abstract

The lighting device ( 11 ) has at least one light generation device ( 12 ) for generating a primary light (P), a first luminophore ( 16 ) for converting the wavelength of the primary light (P) to a first secondary light (S 1 ), and a second luminophore ( 20 ) for converting the wavelength of the primary light (P) to a second secondary light (S 2 ), the first luminophore ( 16 ) being located on a movable support ( 15 ), which is provided in order to alternatively move the first luminophore into and out of a beam path of the primary light (P), and the second luminophore being located on a stationary support ( 21 ). The invention also relates to a method for generating wavelength-converted secondary light from primary light with alternating irradiation of a first luminophore located on a movable support and of a second luminophore located on a stationary support by the primary light. The invention can be used, for example, as a projection device for film and video projection, in endoscopy, for lighting effects in the entertainment industry, for medical irradiations as well as in the automobile industry, in particular as a head light for motor vehicles.

The invention claimed is: 
     
       1. A lighting apparatus, comprising:
 a light generating device for generating a primary light; 
 a first luminophore for the wavelength conversion of the primary light into a first secondary light; and 
 a second luminophore for the wavelength conversion of the primary light into a second secondary light; 
 
       and wherein:
 the first luminophore is situated on a movable carrier, which is configured to alternately introduce and remove the first luminophore into and from a beam path of the primary light, 
 the second luminophore is situated on a stationary carrier, 
 the movable carrier is a rotatable luminophore wheel having a plurality of segments passing through into the beam path of the primary light, 
 at least one luminophore segment comprises the first luminophore, 
 at least one transmitted-light segment is a segment that is transmissive at least for the primary light and the second secondary light, 
 at least one reflector segment is a segment that reflects at least the primary light, 
 primary light emitted by the light generating unit can be radiated through the transmitted-light segment onto the second luminophore, and 
 second secondary light emitted by the second luminophore can be radiated back through the transmitted-light segment. 
 
     
     
       2. The lighting apparatus as claimed in  claim 1 , wherein the lighting apparatus comprises a first color-selective reflection element, which is arranged between the light generating unit and the luminophore wheel and which is configured as transmissive for the primary light emitted by the light genera ting unit and is configured as reflective for the primary light, the first secondary light and/or the second secondary light. 
     
     
       3. The lighting apparatus as claimed in  claim 2 ,
 wherein the first color-selective reflection element is configured as reflective for the primary light reflected by the luminophore wheel, for the first secondary light and for the second secondary light, and 
 wherein the lighting apparatus is configured: 
 in the case of a luminophore segment introduced into the beam path of the primary light, to reflect light emitted by said segment at the first color-selective reflection element; 
 in the case of a reflector segment introduced into the beam path of the primary light, to reflect the primary light radiated onto the reflector segment back onto the color-selective reflection element; and 
 in the case of a transmitted-light segment introduced into the beam path of the primary light, to radiate the light emitted by the second luminophore through the transmitted-light segment onto the color-selective reflection element. 
 
     
     
       4. The lighting apparatus as claimed in  claim 3 ,
 wherein the first color-selective reflection element has a polarization-dependent transmittance for the primary light, and 
 wherein an optical element acts on the primary light and changes a polarization is arranged between the color-selective reflection element and the luminophore wheel. 
 
     
     
       5. The lighting apparatus as claimed in  claim 2 ,
 wherein the first color-selective reflection element is configured as reflective at least for the first secondary light, 
 wherein the lighting apparatus comprises a second color-selective reflection element, which is arranged between the luminophore wheel and the second luminophore and which is configured as transmissive for the primary light radiated through the transmitted-light segment and is configured as reflective for second secondary light emitted by the second luminophore, and 
 wherein the lighting apparatus is configured: 
 in the case of a luminophore segment introduced into the beam path of the primary light, to reflect light emitted by said segment at the first color-selective reflection element; 
 in the case of a reflector segment introduced into the beam path of the primary light, to reflect the primary light radiated onto the reflector segment back onto the first color-selective reflection element; and 
 in the case of a transmitted-light segment introduced into the beam path of the primary light, to radiate the primary light transmitted by said segment through the second color-selective reflection element onto the second luminophore and to reflect second secondary light emitted by the second luminophore by means of the second color-selective reflection element. 
 
     
     
       6. The lighting apparatus as claimed in  claim 5 ,
 wherein the first color-selective reflection element has a polarization-dependent transmittance for the primary light, and 
 wherein an optical element acts on the primary light and changes a polarization is arranged between the color-selective reflection element and the luminophore wheel. 
 
     
     
       7. The lighting apparatus as claimed in  claim 6 , wherein said optical element is a quarter-wave plate. 
     
     
       8. The lighting apparatus as claimed in  claim 2 ,
 wherein the first color-selective reflection element is configured as reflective at least for the second secondary light 
 wherein the lighting apparatus comprises a further color-selective reflection element, which is arranged downstream of the luminophore wheel in a beam path of the reflected primary light and of the first secondary light and downstream of the first color-selective reflection element in a beam path of the second secondary light and which is configured as reflective for the primary light and the first secondary light and is configured as transmissive for the second secondary light, 
 wherein the luminophore wheel is arranged obliquely in the beam path of the primary light, and 
 wherein the lighting apparatus is configured: 
 in the case of a luminophore segment introduced into the beam path of the primary light, to radiate light emitted by said luminophore segment onto the further color-selective reflection element; 
 in the case of a reflector segment introduced into the beam path of the primary light, to radiate the primary light reflected by the reflector segment onto the further color-selective reflection element; and 
 in the case of a transmitted-light segment introduced into the beam path of the primary light, to radiate the light emitted by the second luminophore through the transmitted-light segment onto the first color-selective reflection element and to reflect it there onto the further color-selective reflection element. 
 
     
     
       9. The lighting apparatus as claimed in  claim 1 , wherein the light generating device comprises at least one laser light source. 
     
     
       10. The lighting apparatus as claimed in  claim 1 , wherein:
 the primary light is blue light and one secondary light is green light and another secondary light is red light. 
 
     
     
       11. The lighting apparatus as claimed in  claim 1 , wherein:
 the primary light has a peak wavelength of approximately 445 nm, and 
 one secondary light is green light and another secondary light is red light.